Every time you calculate an order the width must be specified. The same is true when calculating on order section in Signature Acquisition or Signature Throughput Processing.

If it is an order tracked waterfall with no leakage on the orders then the width could be one order line. If it is an FFT based waterfall we need to specify the width to calculate the order to compensate for leakage. We then report the order as the RMS across that width. By default the order width is 0.5 order wide. So, 3rd order would be represented by the RMS level between 2.75 and 3.25 order. To verify the width you could put the waterfall in a colormap display in dB or Log format and use an order cursor to see how wide the order is.

If the width is too narrow then the energy of the order is underestimated, if it it is too wide it is overestimated.